Fungi includes yeasts, molds, rusts and mushrooms. Of the 100,000 known species, only 150 regularly cause disease. Dermatophytes which include tinea ungium are the main cause of onychomycosis the detachment of the nail from its bed at its distal or lateral attachments especially in the dark, sweaty environment of nails. The fungi usually create damage to the nail in the form of micropores. They also cause unsightly discoloration and thickening of the nails and attack the tissue in the nail bed under the nails. Continued presence of the fungi can lead to secondary bacterial infection of the toes or fingers.
20% of the U.S. population between ages 40 and 60 have nail fungus. There are 70 million who have nail and/or skin disease caused by fungi. In 2004, $17.4 billion dollars was spent in the United States for relief. Topical antifungals used for treatment of nail fungal disease are not nearly as effective against tinea capitis and tinea corporis. The following older topical treatments are still available over the counter (OTC).
The old, but still available                Whitfield's ointment        Tolnaftate        Undecylenic acid        Topical amphotercian B        Haloprogin        Castellani's Paint        Cyclopirox        
The following modern OTC topicals are also available. None of these topical treatments provide permanent treatment of nail fungus.
The Modern newer topicals                Azoles (ketoconazole, econazole, et al.)        Polyene antibiotics (nystatin, natamycin)        Allyamines (naftifine HCl, terbinafine)        Hydroxypyridones (ciclopirox)        Morpholines (amorolfine)        
Systematic antifungals such as griseofulvin, amphotericin B, imidazoles, triazoles, flucytosine or terbinafine must be taken for several months while closely monitoring liver enzymes since there is risk of damage to the liver.
The selling price of typical nail fungus medicines is as follows:
MedicationAmountCostLamasil (terbinafine) 90 tablets$971.66Sporanox (traconazole) 84 tablets$797.71Penlac (cyclopiox 8% laquer)6.6 ml$147.00
E. M. Warshaw et al. in a double blind study reported (October 2005, American Academy of Dermatology) that continuous ingestion of Lamisil was far superior to pulse therapy and that continuous therapy only provided 71% mycological cure and 41% complete cure. Cure of all nails only occurred in 25% of the subjects.
Nail lacquers may induce side effects such as sensitization and allergic contact dermatitis (European Journal of Dermatology, Volume 10, Number 3, 223-5, Avril-Mai 2000. In a case study, it was found that after preformed acrylic nails bonded with Ethylcyanoacrylate (ECA) were removed after 3 weeks, oncychomycosis was revealed.